Objective:To investigate the correlation between immune function and age-related pulmonary fibrosis, as well as the potential impact of bacterial lysates on this condition.Methods:Twenty-four healthy male C57BL/6 mice, aged 24, were randomly divided into three groups: a control group(Group N), a pulmonary fibrosis group(Group M), and a pulmonary fibrosis+ bacterial lysis product intervention group(Group P). Mice in Groups M and P were intratracheally injected with bleomycin(5 mg/kg)to induce a mouse pulmonary fibrosis model, while mice in Group N were injected with saline.After modeling, mice in Group P were orally administered 0.4 ml of a bacterial lysis product once a day.After 28 days, lung tissue and blood samples were collected for analysis.Pathological changes in lung tissue were assessed using hematoxylin and tosin staining(HE)and Masson staining and the Ashcroft score.The expression of CD4+ and CD8+ in lung tissue was evaluated using immunohistochemistry.The levels of serum interferon-γ(INF-γ), interleukin-3(IL-13), and immunoglobulin A(IgA)protein were measured using Enzyme-linked Immuno Sorbent Assay(ELISA). The levels of INF-γ and IL-13 mRNA in lung tissue were determined using Real-Time Quantitative Transcription PCR(RT-qPCR). Additionally, the protein expression levels of matrix metalloprotein-9(MMP-9)and tissue inhibitor of metalloproteincise 1(TIMP-1)in lung tissue were assessed using blot analysis.Results:The degree of lung fibrosis was significantly reduced in mice in group P compared with group M when treated with bacterial lysis products.Group M showed a significant decrease in the expression of CD4+ T cells and an increase in the expression of CD8+ T cells( P<0.05)compared to group N. Additionally, the content of IgA was decreased( P<0.05)in group M. On the other hand, group P showed a significant increase in the expression of CD4+ T cells and a decrease in the expression of CD8+ T cells( P<0.05)compared to group M. Furthermore, the content of IgA was elevated( P<0.05)in group P. After bacterial lysis product intervention, mRNA and protein expression levels of IFN-γ were elevated( P<0.05), while mRNA and protein expression levels of IL-13 were reduced( P<0.05). Moreover, protein expression of MMP-9 and TIMP-1 was significantly up-regulated in group M compared with group N( P<0.05), and decreased after bacterial lysis product intervention( P<0.05). Conclusions:It is well-known that immune mechanisms play a crucial role in the development of pulmonary fibrosis.The use of bacterial lysates has been found to effectively regulate immune balance and mitigate the severity of pulmonary fibrosis in elderly mice.

The dihydrofolate reductase (dhfr) and dihydropteroate synthetase (dhps) genes of Plasmodium vivax, as antifolate resistance-associated genes were used for drug resistance surveillance. A total of 375 P. vivax isolates collected from different geographical locations in China in 2009-2019 were used to sequence Pvdhfr and Pvdhps. The majority of the isolates harbored a mutant type allele for Pvdhfr (94.5%) and Pvdhps (68.2%). The most predominant point mutations were S117T/N (77.7%) in Pvdhfr and A383G (66.8%) in Pvdhps. Amino acid changes were identified at nine residues in Pvdhfr. A quadruple-mutant haplotype at 57, 58, 61, and 117 was the most frequent (57.4%) among 16 distinct Pvdhfr haplotypes. Mutations in Pvdhps were detected at six codons, and the double-mutant A383G/A553G was the most prevalent (39.3%). Pvdhfr exhibited a higher mutation prevalence and greater diversity than Pvdhps in China. Most isolates from Yunnan carried multiple mutant haplotypes, while the majority of samples from temperate regions and Hainan Island harbored the wild type or single mutant type. This study indicated that the antifolate resistance levels of P. vivax parasites were different across China and molecular markers could be used to rapidly monitor drug resistance. Results provided evidence for updating national drug policy and treatment guidelines.
Antimalarials/pharmacology* ; China/epidemiology* ; Drug Combinations ; Drug Resistance/genetics* ; Folic Acid Antagonists/pharmacology* ; Humans ; Mutation ; Plasmodium vivax/genetics* ; Prevalence